Several human hepatoma cell lines were previously studied for their ability to synthesize FVIII coagulant antigen. No FVIII coagulant antigen could be detected by immuno-precipitation of 35S metabolically labeled protein from these cells lines nor was any mRNA for FVIII coagulant antigen detectable by hybridization studies with a 32p labeled synthetic oligonucleotide probe for FVIII antigen by assaying conditioned media from a human "prophepatocyte: cell line provided by Dr. Paul Price, Hana Biologics. Immuno-radiometric assay of the conditioned media (and 10X concentrated conditioned media) showed no detectable FVIII antigen.